No description available.

No description available.

Due to the large amount of impervious surface cover, urban areas are at high risk for flooding and, in cities with combined sewer systems, subject to sewer overflow during heavy storm events. The Pennsylvania Department of Transportation (PennDot) is currently reconstructing and expanding parts of Interstate 95 (I-95) through the city of Philadelphia. Due to both federal and local laws, PennDOT must account for the stormwater runoff and minimize outflow to the sewer system. To do so, PennDOT has plans to construct a series of stormwater management practices (SMPs) adjacent to I-95 to control the volumes of highway runoff. In partnership with Villanova University, Temple University has been tasked with monitoring these SMPs, known as bioswales, to provide insight and guidance as the project moves forward and to ensure mistakes aren’t reproduced in future construction. This research is contributing to the overall project goals by testing the application of geophysical monitoring to one of the bioswales known as SMP A. Unlike commonly used point measurements, geophysical surveys are non-invasive and provide extensive spatial coverage. Specifically, this research involves the use of electrical resistivity tomography (ERT), in which a series of cable-connected electrodes are placed in the ground and measure electric potential differences when an electric current is applied. Once processed, the results are a contoured subsurface image of the distribution of electrical resistivity (the inverse of electrical conductivity). If multiple surveys are taken over time, the data can be differenced, known as time lapse inversion, to quantify changes in electrical resistivity. ERT is a favorable for these SMPs as survey results are sensitive to changes in soil moisture and fluid conductivity, which are essential parameters when tracking infiltration and road salt influx at these SMPs. Additionally, the ERT data can be converted to soil moisture values using Archie’s law, which is important for determining soil moisture at points where no sensors are currently placed. We built and installed three ERT survey lines connected to an on-site monitoring station in April 2019 and collected quasi-daily measurements until monitoring seized in November 2021. One way to test SMPs is through a simulated runoff test, in which an SMP is flooded with water from an external source and the SMP’s response is recorded. During September 2020, Villanova University performed an SRT at SMP A, while we performed ERT surveys before, during, and after the SRT to track the infiltration and dry-out cycle. Knowing how long the soil at an SMP takes to recover to pre-storm soil moisture levels is essential in understanding an SMP’s performance and functionality. We were successfully able to capture the wet-up associated with the SRT and the corresponding dry-out period with the ERT data, which showed around a 20% decrease in resistivity when soil sensors indicated saturation. This resistivity change began to decrease and finally reached pre-SRT levels (0 – 5% change) after 68 hours, leading to our estimate of a three day recovery time for SMP A. Interestingly, inflow/outflow measurements at SMP A showed that only 24% of the input water exited the SMP via the overflow drain, meaning the rest of the water remained in the SMP. This discrepancy was solved with our ERT data, which showed that the decrease in resistivity, and therefore increase in soil moisture, was seen at depths beyond the 0.60 m layer of amended fill the SMP contained. Overall, the water was infiltrating past this layer and into the urban soil below. Initially it was thought that the native urban soil would impede infiltration, hence SMP A was designed around this assumption. However, our geophysical results indicate that the native urban soil underlying the SMP has an infiltration rate of 10 cm/hr and is contributing to the overall function of the SMP. This was unknown as previous monitoring was focused on the layer of amended fill material, not the underlying native soil. The relationship between electrical resistivity and soil moisture, fluid conductivity, and porosity is known as Archie’s law, who derived an empirical formula that allows electrical resistivity data to be converted to soil moisture values. However, this equation requires quantifying two parameters, m (also known as the cementation factor) and n, the saturation exponent. Researchers commonly use pre-published values for m and n, or establish site-specific values by fitting Archie’s law to a set of soil moisture and conductivity data. However, as soil is heterogeneous, one set of m and n values may not be accurate across an entire site, especially with the presence of hysteresis, where one soil moisture value can correspond to multiple conductivity values depending on whether the soil is experiencing imbibition or drainage. Additionally, m and n can change over time as soil fabric changes, as well as soil conductivity changes due to the influx of road salt during winter months. In December 2019, we finished installing 16 TEROS12 soil sensors at SMP A, which recorded soil volumetric water content (VWC) and bulk electrical conductivity (bulk EC) every five minutes for nearly two years. These sensors were at six different locations within SMP A at depths of either 0.10 m, 0.30 m, or 0.60 m. We selected 13 storm events and fit Archie’s law to the soil VWC and bulk EC data to get values for m and n. While we were able to find m and n for all events, including events that exhibited hysteresis in soil VWC and bulk EC, each sensor had a different pair of m and n values. This discrepancy was surprising, given that the soil at SMP is a homogeneous, sandy-loam fill with no more than 10% clay. However, even sensors at the same depth show statistically significant differences. We also found that m and n were changing over time, notably m was increasing over time, possibly due to porosity changes. This result indicates that multiple sensors are needed to accurately calculate m and n, even at sites with relatively homogeneous soil. Most notably, the reason why we had success in fitting Archie’s law for every sensor was due to our accounting for changes in porewater conductivity. Most researchers assume a constant value for porewater (fluid) conductivity in Archie’s law. However, we found that not accounting for porewater conductivity changes lead to severe misestimation of soil VWC, even getting physically impossible values (VWC > 1.0 m3/m3) in some cases. Therefore, accounting for changes in porewater conductivity is essential when using Archie’s law. Road salt transport in SMPs is a concern, especially in Philadelphia, which is subject to winter storms and freezing conditions. In some PennDOT SMPs, the presence of road salt in the soil during leaf-out has been suspected to be the cause of stunted plant growth and pre-mature plant mortality. Vegetation is an important aspect of the SMPs, as they provide evapotranspiration pathways, aesthetics, and soil erosion control. Thus, vegetation impairment affects SMP functionality, and plants often need to be replaced, increasing maintenance costs. To track and assess the spatial distribution of road salt, we performed ERT surveys along three lines, with two lines in the topographically lower portion of the SMP, or flood zone, and the other line on the elevated bank parallel to the other lines. All three of these lines had vegetation. In total, we collected 900 ERT surveys from October 2020 to September 2021, sufficiently covering the winter months and growing season. During February 2021, the soil sensors indicated significant increases in conductivity, with sensors ranging from 5.0 – 20.0 mS/cm, compared to pre-winter values of 0.1 – 0.6 mS/cm. The winter ERT surveys show the formation of a shallow conductive (< 10 Ω) layer in the top 0.25 m of soil, and an overall decrease in resistivity of up to 70%. This change decreased over the spring and summer months, indicating that dilute runoff was flushing the salt through the soil column. However, flood-zone ERT data still showed a 20% decrease in resistivity in June when compared to pre-winter data, indicating that road lingered in the soil during the spring and summer months. In May, we began taking bimonthly measurements of plant height, width, and leaf chlorophyll content (SPAD) on plants along the ERT lines, then in July took leaf tissue, root tissue, and root-zone soil samples and analyzed them for sodium content. We found that the plants along Lines 2 and 3 (flood-zone) had statistically significant stunted growth when compared to the plants along the elevated bank, as well as elevated sodium levels (> 400 mg/kg) in root tissue. No detectable sodium was found in leaf tissue samples. The stunted growth and elevated root sodium in the flood-zone plants indicate that early spring storms are not enough to flush out the road salt, and therefore artificial flooding may be required before leaf-out to ensure plant survival. We also suggest planting salt-tolerant plant species in areas of SMPs prone to flooding, such as the topographically lower portions. ERT can also be used to guide the placement of these plant species, as ERT can delineate areas of higher conductivity. / Geoscience

Urbanized areas with increased amounts of impervious surfaces alter hydrologic systems by increasing stormwater runoff, decreasing infiltration, and reducing vegetation cover and evapotranspiration. Modeling hydrologic systems here is especially difficult due to the increased impervious land cover, which makes predicting processes such as urban streamflow and flooding challenging. By understanding the drivers of hydraulic processes, such as soil characteristics, bedrock depth, and land use, the quality and accuracy of models can be improved. The goal of this study was to use soil moisture loggers and electrical resistivity tomography (ERT) along the Pennypack Creek (Philadelphia, PA) to evaluate soil infiltration and bedrock depth in urban areas to ultimately access their impact on critical zone modeling. ERT was also used to validate or dispute recent seismic interpretations. Four study sites adjacent to Pennypack Creek were selected based on variations in underlying geology: Triassic basin sedimentary rock (Lukens), Paleozoic mafic gneiss (Meadow), Piedmont mica schist (Pine Road), and coastal plain weathered down to mica schist (Rhawn Street). Soil moisture sensors were installed at each site to a depth of up to 50 cm. ERT surveys were conducted at Pine Road and Rhawn Street sites. High infiltration variation at Pine Road and Meadow indicated macropores, which create preferential flow paths whereas low infiltration variation at Rhawn Street and Lukens indicated compaction associated with their land use (public parks). Comparing field capacity data to USDA soil type maps indicated the soil type was not a good predictor and in situ sampling was needed to estimate soil properties. ERT demonstrated bedrock was not shallow at the streambed as predicted by the seismic inversion and showed the need to corroborate depth to bedrock from seismic surveys beneath streams with resistivity inversions. Structure beneath the streambed was particularly noisy for the seismic surveys due to the flow of stream water. This study demonstrates that an accurate critical zone model, especially at urban sites, must rely on in situ investigation of hydrologic parameters based on land use, rather than assumptions of parameter values based on the underlying geology or soil type. / Geology

No description available.

京都大学 / 新制・課程博士 / 博士(工学) / 甲第23491号 / 工博第4903号 / 新制||工||1766(附属図書館) / 京都大学大学院工学研究科都市社会工学専攻 / (主査)教授 小池 克明, 教授 岸田 潔, 准教授 奈良 禎太 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

Целью работы являлось исследование структурных и электрических свойств фуллерита С70 в диапазоне давлений до 50 ГПа. Воздействие высоких давлений и температур является эффективным средством для создания метастабильных фаз углерода, и, возможно, получения сверхтвердых алмазоподобных соединений. Этим фактом обусловлена актуальность исследования фуллерена С70 и изучения его свойств при высоких давлениях, а также условий формирования новых фаз и процессов их релаксации. / The aim of the work was to study the structural and electrical properties of fullerite C70 in the pressure range up to 50 GPa. Exposure to high pressures and temperatures is an effective means to create metastable phases of carbon, and possibly to obtain superhard diamond-like compounds. This fact determines the relevance of the study of fullerene C70 and the study of its properties at high pressures, as well as the conditions for the formation of new phases and the processes of their relaxation.

京都大学 / 新制・課程博士 / 博士(工学) / 甲第24617号 / 工博第5123号 / 新制||工||1979(附属図書館) / 京都大学大学院工学研究科材料工学専攻 / (主査)教授 田中 功, 教授 奥田 浩司, 教授 安田 秀幸 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

Roll-along electrical resistivity surveying was used with seismic refraction, magnetometer and gravity surveying in geophysical characterization of sites with a specific environmental or engineering problem. Three examples are presented where resistivity surveying provided vital constraints on acquisition and interpretation of other data in chaotic terrane. A commercially resistivity meter was used with prototype equipment designed, assembled, and tested at Virginia Tech. The equipment included a multiconductor cable consisting of interchangeable segments and a circuit allowing selection of numerous electrode configurations. The Sinking Creek Landfill, a 10-acre site, was used for disposal of municipal waste in the early 1970’s. Roll-along resistivity proved to be the most useful geophysical tool in ascertain its internal structure. Wenner configuration resistivity data, sensitive to both conductive leachate and ferrous metals, showed trenches within the landfill displayed in profile. Magnetic field measurements revealed anomalies over some trenches suggesting a method for discriminating between ferrous metal and leachate. Results of a resistivity survey can help planners of a refraction survey avoid low velocity “blind” layers. The Mid County Landfill borrow area is a 26 acre site situated within the Max Meadows Breccia and used for cover material for an adjacent landfill, The engineering problems were to measure the volume of rippable material, but travel time data were somewhat ambiguous. The refraction data interpreted using a) conventional 3-layer analysis b) horizontal 3-layer analysis of single shots, and c)continuous velocity gradient analysis of single end shots were compared with auger refusal depth. The single end horizontal analysis matched auger refusal depths most closely. Roll-along resistivity pseudo-sections made along the refraction lines proved to be effective for qualitatively imaging pinnacles and megaclasts. Excavation of fill material from a 75 acre river terrace in Pembroke exposed an antiform cut by high angle, near surface faults. Geophysical characterization was undertaken to determine the thickness of the alluvial deposit, and the relationship of the faults with structures in the underlying bedrock. Seismic refraction showed the terrace was as much as 134 feet thick. Resistivity pseudosections revealed a resistivity anomaly associated with the graben could be detected for a horizontal distance of several hundred feet. A gravity gradient paralleling the resistivity anomaly extends the feature more than 1000 ft from the exposed structure. Tenuous evidence of a bedrock escarpment beneath the near surface structure is found in a combination of seismic refraction, gravity, and electrical resistivity data. Roll-along resistivity has proved to be key to geophysical interpretation of these three areas. Images displayed on pseudosections reveal lateral inhomogeneity more clearly than could be discerned from seismic, gravity and magnetic data. Roll-along resistivity data can provide information for efficient siting of additional geophysical studies. / Ph. D.

Yes / This paper summarizes the results of a recent geophysical investigation carried out at Porolissum, which is considered to be one of the most significant Roman sites in Romania. The geophysical survey was carried out within the latus dextrum of the fort, which is the same location that had been the subject of earlier geophysical surveys as well as older archaeological excavations (1970s) that had uncovered a multiroom building. A cesium vapor total field magnetometer and a multi-electrode resistivity meter for a dense Electrical Resistivity Tomography (ERT) survey were used. Eighty parallel ERT profiles in combination with the emerging total field magnetic data and an antecedent magnetic survey allowed us to complete a more precise interpretation regarding the building that once existed on the left side of Porolissum’s Principia (the commander’s house). In contrast to the magnetic survey, which only reveals a part of the building’s architecture, the ERT survey provides a comprehensive view of the structure’s layout. More than 20 rooms could be positively identified, and the existence of further rooms might be deduced from the data. The ERT scan revealed the existence of the building’s northern external wall as well, which is not reflected on the magnetic map. Because some parts of the building are not visible on the magnetic map, we can assume that the building was constructed with at least two types of rocks (magmatic and sedimentary). In addition to the archaeological interpretation of the geophysical anomalies, a number of discussions concerning the connection between our survey and the geology of the area were held. The complementarity of the magnetic and resistivity results prompted us to conceive a preliminary 3D reconstruction of the building. Even if the building function is unknown in the absence of reliable archaeological data, it could have been a storage building, a second praetorium, a valetudinarium (hospital), or an armamentarium (weapons storage building). The illustrative reconstruction was completed taking into consideration that the building was a Roman military hospital, which, based on the available data, may be considered a credible assumption.